Draw hook toggle latch mechanism



0. A- SWANSON DRAW HOOK TOGGLE LATCH MECHANISM Oct. 26, 1965 2 Sheets-Sheet 1 Filed July 5, 19 5 INVENTOR.

Oscar A. Swanson Oct. 26, 1965 o. A. SWANSON 3,214,207

DRAW HOOK TOGGLE LATCH MECHANISM Filed July 5, 1963 2 Sheets-Sheet 2 5O 1 I F! G. 8 ess uhw INVENTOR.

Oscar-A. Swanson F'iGzlQ FIGH United States Patent 3,214,207 DRAW HOOK TQGGLE LATCH MEtIHANldP/I @scar Alfred Swanson, 5559 Alrnar Ave, Pacific Palisades, (Ialif. Filed duly 5, 1963, Ser. No. 292,828 11 Claims. (Ci. 292-66) This invention relates to draw hook toggle latch mechanisms which are adapted to containers and the like in either substantially flush relationship or wholly external to the outer surfaces. This invention will result in increased safety and improved ease of operation.

The general object of my invention is to provide a latch mechanism with extreme ease of operation and having very positive locking features to insure increased safety.

A further object of my invention is to have .a latch with an eflicient arrangement of structural components resulting in lightweight rugged construction and ease of manufacture.

It is another object of my invention to provide a latch of the type invented which is easily adjustable to compensate for various dimensional tolerance in container installations.

Other objects and advantages of the invention will be apparent from the following description and accompanying drawings in which similar characters of reference indicate similar parts throughout the several views.

Referring to the drawings:

FIG. 1 is a front elevational View of a substantially flush installation of my draw hook toggle latch mecha nism embodying a preferred form of my invention;

FIG. 2 is a side sectional view wherein the section is taken substantially .as indicated by line 22 and accompanying arrows in FIG. 1, the latch mechanism being shown in its latched position and the container on which it is installed is illustrated fragmentarily in dot and dash lines;

FIG. 3 is a side sectional view of the invention, wherein the latch mechanism is shown in its released position and the two portions of the container which are to be drawn together and fastened are shown fragmentarily in dot and dash lines;

FIG. 4 is a side elevational view wherein the draw hook is modified; an adjustable threaded end is provided;

FIG. 5 is a side elevational view of a resilient spring which is adapted to use in the mechanism as shown in FIGS. 2 and 3, the portions of the spring being illustrated in their closed position;

,. FIG. 6 is a side elevational view of a second resilient spring which is adapted to use in the mechanism as shown in FIGS. 2 and 3, the portions of the spring being illustrated in their closed positions;

FIG. 7 is a front elevational view showing a non-fiush form of my invention in which the parts are of modified structure from those described and depicted in FIGS. 1 to 6 inclusive;

FIG. 8 is a side sectional View of the modified structure shown in FIG. 7 depicting it in its holding position;

FIG. 9 is a side sectional View of the modified structure shown in FIG. 7 depicting it in its released position;

FIG. 10 is a side elevational view of a resilient spring which is adapted to use in the mechanism shown in FIGS. 7 to 9 inclusive;

FIG. 11 is a side elevational view of a second resilient spring which is adapted to use in the mechanism shown in FIGS. 7 to 9 inclusive.

In use, the illustrated draw hook toggle latch is shown in forms adapted for containers, or the like, requiring quick opening and dependable rugged fastening. The illustrated forms of the latch allow the user the choice dlld zh'i Patented Get. 26, 1965 of either a substantially flush installation or one that can be mounted on the outside surface of the container, however the invention mechanism can be adapted to a modified form which is partially submerged in the container body. The latch is provided with .a mechanism that provides for positive locking in the latched position wherein the tension loading applied to the draw hook by the container, upon which it is installed, forcibly holds the mechanism locked.

Having reference to the drawings, and particularly FIGS. 1 to 6 inclusive, my draw hook toggle latch mechanism has a support mounting bracket 21 having a mounting surface 22 and having holes 23 therein for inserting fastening means, such as bolts or rivet 24, by which the bracket is fastened to the container structure, upon which the latch is to be mounted. The support mounting bracket 21 having an integral central well portion 25 with side walls 26 extending vertical to mounting surface 22 and having their surfaces parallel longitudinally to and symmetrical to a longitudinal center line of the latch.

A latch actuator 27 consisting of a channel member having side portions 28 which fit movably between the side walls as of the support bracket 21 and an extended end portion which extends longitudinally over one end of support bracket 21.

A cross pin 29 extending through aligned holes in the side walls as of the support bracket 21 and through the longitudinal central portion of the latch actuator 27 side walls 28 to support said latch actuator for rocking movement.

A bell crank 30 located at the opposite end of the support bracket from the latch actuator 27, consisting of plate form, and supported for limited rotational movement between the sidewalls 26 of the support bracket 21 by a cross pin 31. The cross pins 29 and 31 are fixed axes which are in parallel alignment to each other.

A link 32, consisting of two flat plates, is connected between the latch actuator 27 and the bell crank 30 to provide an operating connection and extends between their adjacent and aligned end portions and is movably connected thereto by cross pin 33 at the actuator end and cross pin 34 at the bell crank end.

At the opposite end portion of the support bracket 21 from the latch actuator support pin 29 and in a position aligned to said latch actuator is a draw hook 35 which is rotationally attached to the bell crank 30 by a cross pin 36 at the end of the bell crank opposite from the link 32 attachment. The draw hook has that portion 37 covered by and in contact with the latch actuator. At the end of the draw hook, opposite from the attachment to bell crank 30, is an adjustable hook 38 and secured to the draw hook body fastening means, such as a bolt 39*.

A spring 4d, of the torsion type, with coiled portion 41 surrounding the cross pin 34 of the link 32 and bell crank 30 connection, and having two end portions, one of which 42 is connected to cross pin 33 of the link 32; and actuator 27 connection and 43, the other connected to the cross pin 31 which supports the bell crank. Spring is used to positively bias the mechanism parts toward the position to which they are last operated. In the latched position of the spring, as indicated in FIG. 5 by lines a and c, the spring is under stress and exerts biasing force against the engaged cross pins 31 and 33 holding the mechanism in that position. In the released position of the spring, as indicated in FIG. 5 by lines a and d, the spring is under stress and exerts biasing force against the engaged pins 31 and 33 holding the latch in the released position.

In the unwound position of the spring, as depicted in FIG. 5, the arm portions assume angles indicated by lines a and b. The direction of the biasing force on the toggle parts of the latch mechanism changes between released and holding positions when the axis of the cross pin 33 crosses the plane passing through the axes of the cross pins 29 and 31.

To insure retraction of the draw hook 35 when the latch is in the released position, and to insure its actuation by the latch actuator to the latched position, a torsion spring 44 is provided. Spring 44 is illustrated in FIG. 6 and shown in operative arrangement in FIGS. 1 to 3 inclusive. The spring 44 has a coil portion 45, a hook formed end portion 46 and a straight end portion 47. In the depicted mechanism as shown in FIGS. 1 to 3 inclusive, the coil portion 45 surrounds the cross pin 36 which connects the draw hook to the bell crank 30. The hook end portion 46 engages the cross pin 31 and the straight end portion 47 bears against the draw hook under stress at all times with sufficient force to cause the draw hook to a position against the latch actautor 27 when the latch is in the released position.

In use, the illustrated draw hook toggle latch mechanism is operated manually by hand or fingers. If a maximum amount of draw is needed, the draw hook is pushed by finger to a position for engagement, after which, the latch actuator is pressed by hand to operate the mechanism which draws the draw hook in a longitudinal direction pulling the components of the container, or the like, on which the latch is mounted, together to accomplish latching. When only a moderate amount of draw is needed to fasten the components of a container upon which the latch is used, the latch actuator alone is operated effecting operation of all the mechanism including positioning the draw hook, completing the drawing and latching.

In the modified structure of my draw hook toggle latch mechanism which is illustrated in FIGS. 7 to 11 inclusive the latch parts including the support mounting bracket and all the mechanism is modified considerably because of the external installation.

The modified embodiment of my invention has a support mounting bracket 48 having a mounting surface 49 and having holes 50 for the accommodation of fastening means, such as bolts or rivets, by which said bracket is attached to the surface of the container structure upon which the invention is to be mounted. The support bracket 48 consisting of a flat base having two walls 51 extending at right angles about a longitudinal center line to which it is symmetrical.

A latch actuator 52 consisting of a channel member having side portions 53 which fit movably between the side walls 51 of the support bracket 48.

A cross pin 54 extending through aligned holes in the side walls 51 of the support bracket 48 and through the longitudinal central portion of the latch actuator 52 side portions 53 to support latch actuator for rocking movement.

A bell crank 55 located at the opposite end of the support bracket 48 from the latch actuator 52, and of channel section, and supported for limited rotational movement between the sidewalls 51 of the support bracket 48 by a cross pin 56. The cross pins 56 and 54 are fixed axes which are in parallel alignment to each other.

A link 57, of channel section, and having extended arm 58, is connected between the latch actuator 52 and the bell crank 55 to provide an operating connection and extends between their adjacent and aligned end portions and is movably connected thereto by cross pin 59 at the actuator end and cross pin 60 at the bell crank end.

At the opposite end portion of the support bracket 48 from the latch actuator 52 and in a position aligned to said latch actuator is a draw hook 61 which is rotationally attached to the bell crank 55 by a cross pin 62 at the end of the bell crank opposite from the link 57 attachment. The draw hook has that portion 63 in contact with the link extended arm 58. At the end of the draw hook opposite from the attachment to bell crank 55, is an integral hook.

To provide for engagement of the draw hook 61 and accomplish latching an adjustable hook lug 64 having serrated end portion 65 and mating plate 66 is fastened to the container body component 67 by fastening means such as a bolt 68. The two components of the container upon which the latch is mounted 6'7 and 69 are drawn together when latch is operated.

A spring '76, of the torsion type, with coiled portion 71 surrounding the cross pin 60 and having two end portions one of which 72 is connected to cross pin 59 and the other 73 is connected to the cross pin 56. Spring 71? is used to positively bias the mechanism parts toward the position to which they are last operated. In the latched position of the spring, as indicated in FIG. 10 by lines m and n, the spring is under stress and exerts biasing force against the engaged cross pins 59 and 56 holding the mechanism in the latched position. In the released position of the spring, as indicated in FIG. 10 by lines In and 0, the spring is under stress and exerts biasing force against the engaged pins 59 and 56 holding the mechanism in the released position. In the unwound position of the spring as depicted in FIG. 10, the arm portions assume angles indicated by lines In and p.

The direction of the biasing force on the toggle parts of the latch mechanism changes between released and holding positions when the axis of the cross pin 59 crosses the plane passing through the axes of the cross pins 54 and 56.

To insure retraction of the draw hook 61 when the latch is in the released position, and to insure its actuation by the link' 57 extended arm 58 to the latched position, a torsion spring 74 is provided. Spring 74 is illustrated in FIG. 11 and shown in operative arrangement in FIGS. 7 to 9 inclusive. The spring 74 has a coil portion 75, a hook formed end portion 76 and a straight end portion 77. In the depicted mechanism as shown in FIGS. 7 to 9 inclusive, the coil portion surrounds the cross pin 62. Straight end portion 77 bears against the draw hook 61 under stress at all times with sutficient force to cause the draw hook to a position against the link 57 extended arm 58 when the latch is in the released position.

In use, the modified draw hook toggle latch is as described previously, operation being by fingers and hand.

From the above description of several typical illustrative forms of the invention, the underlying principles thereof will be readily gathered. It is of course to be tinderstood, however, that the particular embodiments of the invention herein disclosed are for illustrative purposes only, and that various changes in design, structure and arrangement may be made therein without departing from the spirit and scope or" the invention or of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A draw hook toggle mechanism latch, the combination comprising, a support mounting bracket, a latch actuator, a bell crank, a link, a draw hook, a biasing spring and a torsion spring, said support mounting bracket providing support for latch actuator and bell crank by means of two cross pins in aligned relationship at opposite ends of support mounting bracket and about which the latch actuator and the bell crank are rockable about their central portions on fixed axes when mechanism is operated, said link having opposite ends rotatably connected to the bell crank and the latch actuator by cross pins providing axes which move during latch operation, said draw hook having a hook portion at one end, having the other end rotatably connected to the bell crank at end opposite from link connection by a pin whose axis moves through an arc to provide drawing motion to the draw book when the mechanism is operated, a torsion spring mounted under stress with coil portion surrounding pivot axis pin of draw hook and having end portions one of which is secured by the fixed axis pivot cross pin of said bell crank and the other bearing against the draw hook with force causing said draw hook to retract from latched engagement and bear against the latch actuator when the latch is in the released position, a second torsion spring mounted under stress having coiled portion surrounding the cross pin which joins said link to said bell crank and having end portions one of which is secured to fixed pivot axis cross pin of said bell crank and the other secured to the cross pin joining said link to said actuator, said second torsion spring exerting biasing force to the actuator forcibly holding it to the position to which it is last actuated.

2. In a draw hook toggle latch mechanism as defined in claim 1, and wherein the fixed axes of latch actuator and the bell crank and movable axes of the link have a relationship to each other in the latched position whereby a plane passed through the movable axes of the link does not intersect the plane passing through the fixed axes of the latch actuator and bell crank at any point between or at said fixed axes, in the latched position a plane passing through movable axes of the link cross pins is divergent and at an acute angle to a plane passing through the fixed cross pin axis of the latch actuator and the movable axis of link end attached to hell crank, said movable cross pin axis of link at attachment to latch actuator and the fixed pin axis of the bell crank being on opposite sides of a plane passing through actuator pin fixed axis and the link cross pin movable axis attached to the bell crank, in a released position of mechanism movable axes of the link being on opposite sides of a plane passing through fixed cross pin axes of the latch actuator and the bell crank with the link cross pin axis at the bell crank attachment remaining on same side of said plane as in latched position.

3. In a draw hook toggle latch mechanism as defined in claim 1, and wherein the relationship of the mechanism parts and fixed pivot axes and movable axes have an arrangement whereby the tension force applied to the draw hook by installation loads in the latched position causes a rotational moment force on the bell crank which applies a compression force to the link and which applies a rotational moment to the latch actuator forcibly holding it in the latched position and causing it to bear against the draw hook in a direction to forcibly hold it latched.

4. In a draw hook toggle latch mechanism as defined in claim 1, and wherein the relationship of latch actuator and draw hook in the latched position provides for one end portion of said latch actuator to have an inner surface overlapping said draw hook and together lie in close proximity.

5. In a draw hook toggle mechanism as defined in claim 1, and wherein the draw hook is adjustable in a longitudinal direction having a threaded engagement connection with pin joining it to bell crank.

6. In a draw hook toggle latch mechanism -as defined in claim 1, and wherein the draw hook is adjustable in a longitudinal direction having a hook end provided with means for adjustment.

7. In a draw hook toggle mechanism latch as defined in claim 1, and wherein the actuating parts thereof are substantially flush with surface of container or the like, on which it is installed, in the latched position.

8. In a draw hook toggle latch mechanism as defined in claim 1, and wherein the latch actuator is one piece and in latched position lying over all of the mechanism parts.

9. In a draw hook toggle latch mechanism as defined in claim 1, and wherein the support mounting bracket is of one piece construction adapted to mount substantially flush with surface of container or the like on which it is installed.

10. In a draw hook toggle mechanism latch, the combination comprising, a support bracket, a latch actuator, a bell crank, a link, a draw hook, a biasing spring and a torsion spring, said support bracket providing support for the latch actuator and the bell crank by means of two cross pins at its opposite ends and about which the latch actuator and the bell crank are rockable on fixed axes when the mechanism is operated, said link having the opposite ends rotatably connected to the bell crank and the latch actuator by two cross pins which provide axes which move during latch operation, said draw hook having a hook portion at one end and having the other end rotatably connected to the bell crank at the end opposite from the link connection by a pin whose axis moves through an arc to provide both drawing and releasing motions to the draw hook when the mechanism is operated, said biasing spring is mounted under stress and exerts biasing force to the latch actuator and forcibly holds it and the mechanism to the position to which it is last actuated, said torsion spring is mounted under stress and causes said draw hook to bear against the latch actuator when the latch is in the released position, and said latch actuator is rockable in opposite directions by finger pressure to efiect latching or unlatching of the mechanlsm.

11. In a draw hook toggle latch mechanism as defined in claim 19 wherein after the draw hook is rotated to the engaged position by finger pressure applied to its hook end, a drawing movement of the draw hook to the latching position of the mechanism is effected by a rocking movement applied to one end of the latch actuator by finger pressure.

References Eited by the Examiner UNITED STATES PATENTS 2,710,214 6/55 Summers 292-413 3,129,025 4/64 Krueger 292-113 M. HENSON WOOD, IR., Primary Examiner.

ALBERT H. KAMPE. Examiner. 

1. A DRAW HOOK TOGGLE MECHANISM LATCH, THE COMBINATION COMPRISING, A SUPPORT MOUNTING BRACKET, A LATCH ACTUATOR, A BELL CRANK, A LINK, A DRAW HOOK, A BIASING SPRING AND A TORSION SPRING, SAID SUPPORT MOUNTING BRACKET PROVIDING SUPPORT FOR LATCH ACTUATOR AND BELL CRANK BY MEANS OF TWO CROSS PINS IN ALIGNED RELATINSHIP AT OPPOSITE ENDS OF SUPPORT MOUNTING BRACKET AND ABOUT WHICH THE LATCH ACTUATOR AND THE BELL CRANK ARE ROCKABLE ABOUT THEIR CENTRAL PORTIONS ON FIXED AXES WHEN MECHANISM IS OPERATED, SAID LINK HAVING OPPOSITE ENDS ROTATABLY CONNECTED TO THE BELL CRANK AND THE LATCH ACTUATOR BY CROSS PINS PROVIDING AXES WHICH MOVE DURING LATCH OPERATION, SAID DRAW HOOK HAVING A HOOK PORTION AT ONE END, HAVING THE OTHER END ROTATABLY CONNECTED TO THE BELL CRANK AT END OPPOSITE FROM LINK CONNECTION BY A PIN WHOSE AXIS MOVES THROUGH AN ARC TO PROVIDE DRAWING MOTION TO THE DRAW HOOK WHEN THE MECHANISM IS OPERATED, A TORSION SPRING MOUNTED UNDER STRESS WITH COIL PORTION SURROUNDING PIVOT AXIS PIN OF DRAW HOOK AND HAVING END PORTIONS ONE OF WHICH IS SECURED BY THE FIXED AXIS PIVOT CROSS PIN OF SAID BELL CRANK AND THE OTHER BEARING AGAINST THE DRAW HOOK WITH FORCE CAUSING SAID DRAW HOOK TO RETRACT FROM LATCHED ENGAGEMENT AND BEAR AGAINST THE LATCH ACTUATOR WHEN THE LATCH IS IN THE RELEASED POSITION, A SECOND TORSON SPRING MOUNTED UNDER STRESS HAVING COILED PORTION SURROUNDING THE CROSS PIN WHICH JOINS SAID LINK TO SAID BELL CRANK AND HAVING END PORTIONS ONE OF WHICH IS SECURED TO FIXED PIVOT AXIS CROSS PIN OF SAID BELL CRANK AND THE OTHER SECURED TO THE CROSS PIN JOINING SAID LINK TO SAID ACTUATOR, SAID SECOND TORSION SPRING EXERTING BIASING FORCE TO THE ACTUATOR FORCIBLY HOLDING IT TO THE POSITION TO WHICH IT IS LAST ACTUATED. 